4,012,131 research outputs found
Measuring the Welfare Costs of Inflation in a Life-cycle Model
In macroeconomics, life-cycle models are typically used to address exclusively life-cycle issues. This paper shows that modeling the life-cycle may be important when addressing public policy issues, in this case the welfare costs of inflation. In the representative agent model, the optimal inflation rate is characterized by the Friedman rule: deflate at the real interest rate. In the corresponding life-cycle model, the optimal inflation rate is quite high: for the benchmark calibration, it is around 95% per annum. Much of the paper is concerned with understanding this result. Briefly, in the life-cycle model there are distributional consequences of injecting money via lump-sum transfers. The net effect is to transfer income from old, rich agents to young, poor ones. These transfers twist the age-utility profile in a way that agents find desirable from a lifetime utility point of view. A second issue concerns how to assess the costs of inflation in a life-cycle model. Metrics that are equivalent in the representative agent model can give very different answers in a life-cycle model.monetary policy, inflation, welfare costs, life-cycle model
Life-cycle of fatigue sensitive structures under uncertainty
Fatigue is the one of the main contributors to problems related to structural safety of civil and marine structures. Life-cycle management (LCM) techniques considering various uncertainties can be used to predict the safe service life of fatigue sensitive structures, plan for their future inspections and support the decision making process regarding maintenance and repair actions. This paper provides a brief overview of the LCM of fatigue sensitive civil and marine structures under uncertainty. Probabilistic performance prediction, inspection scheduling and maintenance optimization for such structures are discussed
Life cycle analysis of road construction and use
Both the construction and use of roads have a range of environmental impacts; therefore, it is important to assess the sources of their burdens to adopt correct mitigation policies. Life cycle analysis (LCA) is a useful method to obtain demonstrable, accurate and non-misleading information for decision-making experts. The study presents a "cradle to gate with options" LCA of a provincial road during 60 year-service life. Input data derive from the bill of quantity of the project and their impacts have been evaluated according to the European standard EN 15804. The study considers the impacts of the construction and maintenance stages, lighting, and use of the vehicles on the built road. The results obtained from a SimaPro model highlight that the almost half of impacts took place during the construction stage rather than the use stage. Therefore, the adoption of environmentally friendly road planning procedures, the use of low-impact procedures in the production of materials, and the use of secondary raw materials could have the largest potential for reducing environmental impacts
Solar cycle 25: another moderate cycle?
Surface flux transport simulations for the descending phase of cycle 24 using
random sources (emerging bipolar magnetic regions) with empirically determined
scatter of their properties provide a prediction of the axial dipole moment
during the upcoming activity minimum together with a realistic uncertainty
range. The expectation value for the dipole moment around 2020 G)
is comparable to that observed at the end of cycle 23 (about G). The
empirical correlation between the dipole moment during solar minimum and the
strength of the subsequent cycle thus suggests that cycle 25 will be of
moderate amplitude, not much higher than that of the current cycle. However,
the intrinsic uncertainty of such predictions resulting from the random scatter
of the source properties is considerable and fundamentally limits the
reliability with which such predictions can be made before activity minimum is
reached.Comment: 13 papges, 4 figures,Accepted for publication in ApJ
cycle
Algorithm for identification of piecewise smooth hybrid systems; application to eukaryotic cel
Cycle packing
In the 1960s, Erd\H{o}s and Gallai conjectured that the edge set of every
graph on n vertices can be partitioned into O(n) cycles and edges. They
observed that one can easily get an O(n log n) upper bound by repeatedly
removing the edges of the longest cycle. We make the first progress on this
problem, showing that O(n log log n) cycles and edges suffice. We also prove
the Erd\H{o}s-Gallai conjecture for random graphs and for graphs with linear
minimum degree.Comment: 18 page
Cycle structure of random permutations with cycle weights
We investigate the typical cycle lengths, the total number of cycles, and the
number of finite cycles in random permutations whose probability involves cycle
weights. Typical cycle lengths and total number of cycles depend strongly on
the parameters, while the distributions of finite cycles are usually
independent Poisson random variables.Comment: 22 pages, 2 figure
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